Abstract: A first optical memory disc and a second optical memory disc are fixed to each other by an adhesive layer so as to form a dual-surface optical memory disc. In a manufacturing step, an adhesive, preferably pre-cured photo-polymer mixed with spherical spacer elements, is painted on either one of or both of the first and second optical memory discs. When a predetermined pressure is applied between the two optical memory discs, the thickness of the adhesive layer is fixed by the diameter of the spherical spacer elements. While the pressure is applied between the two optical memory discs, ultraviolet rays are applied to the adhesive layer through one of the first or second optical memory discs so as to cure the photo-polymer, thereby tightly joining the first and second optical memory discs to each other.

Abstract: A magneto-optic memory element includes a GdTbFe recording layer sandwiched between a pair of transparent AlN dielectric layers. At least one of the pair of transparent AlN dielectric layers is extended to have a size larger than the GdTbFe recording layer so as to cover the peripheral edge of the GdTbFe recording layer, thereby protecting the GdTbFe recording layer from oxygen and moisture. An Al-Ni alloy reflection film is formed on one of the pair of transparent AlN dielectric layers in order to increase the apparent Kerr rotation angle produced by the magneto-optic memory element.